Abstract
Four cyanido‐bridged Mn^III^–Cr^I^ heterodimetallic complexes have been synthesized by the reactions of Mn^III^ Schiff‐base complexes with the [Cr(CN)~5~(NO)]^3–^ building block. X‐ray diffraction analysis reveals that [Mn(5‐Cl‐salen)(H~2~O)~2~][Mn~2~(5‐Cl‐salen)~2~(H~2~O)~1.5~Cr(CN)~5~(NO)] (1) has a trinuclear structure, and [Mn~3~(salen)~3~(H~2~O)(CH~3~CN)Cr(CN)~5~(NO)]·0.5CH~3~CN·0.5MeOH·2H~2~O (2) and [Mn(5‐Br‐salen)(H~2~O)(CH~3~OH)][Mn~2~(5‐Br‐salen)~2~(CH~3~OH)Cr(CN)~5~(NO)]·2H~2~O (3) have novel 1D chain topological structures, whereas [{Mn(saltmen)}~4~Cr(CN)~5~(NO)]ClO~4~·3H~2~O (4) displays a 2D layered network structure. Magnetic measurements show that the magnetic interaction between the Mn^III^ and Cr^I^ ions bridged by a cyanido group is antiferromagnetic for complexes 1–4. The magnetic fitting for the trinuclear complex 1 gives the magnetic coupling constant J = –10.4(1) cm^–1^ and J′ = –1.29(2) cm^–1^ based on the isotropic Hamiltonian Ĥ = –2__JŜ__~Cr~[Ŝ~Mn(1)~ + Ŝ~Mn(2)~] – 2__J′Ŝ__~Mn(1)~Ŝ~Mn(2)~. Complex 2 exhibits 3D antiferromagnetic ordering (T~N~ = 3.5 K) with a metamagnetic character below T~N~. Complex 3 exhibits an obvious frequency‐dependent AC magnetic susceptibility below 4.0 K, which is due to the spin‐glass behavior. The layered complex 4 displays 3D ferromagnetic ordering with T~c~ = 6.4 K due to the ferromagnetic interaction between the ferrimagnetic layers. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)